Refining of copper



Patented July 25, 1933 ,Josnrn rrnnnn LEEMANS, F ,HOBOKEN LELANVERS, BJiiIiGIUM, "nssrenon To sooin'rn 'GENERALE*METALL RGIQUE BELGIUM v a No'Dra'wing. Applieat ion filed'June 2a, 193i; serial no. 546,155, and 31' Germany Janu-ary 3,1931. I

Y jThis invention relates to a process for the refining of black copper, with a View to ob:

taining anodes for electrolytic refining, and applies more particularly to very impure blackcopper, containing'for i'nst'ancefrom 80 'to' 95% {of copper, the impurities being mainly metals of the-iron group, suchas iron, cobalt and nickel. I H V Hitherto, the black copper was charged in a flame oven, called anode furnacelhaying for'it's' function to smelt the copper, to effect the oxidation of the impurities by concentrating the latter in a slag which floats at the surface of the molten bath, to reduce by poling the oxide of copper which has been formed during the previous operation, and

lastly to cast 'the'refined copper'inthe form of-anodes with a View to electrolytic treat-- vment. g

During the operation of refining in the anode furnace, a more or less important 'amount of slag is produced, according to the percentage of impurities contained by the blackcopper;

5o: refining operation, is partly-in oxide form.

- This slag may contain upto 35% of copper or more, partly in metallic form, partly in the formof oxides orsilicates.

The recovery of the copper contained in #30 the slags obtained by the refining operation was hitherto effected by meltingthe slag in the presence of coke and of fluxes. This op: eration is carried apartfrom the smelting sumption of fuel. v p Y It has been ascertained that by smelting the slag obtained from the refining of blackcopper in the presence of a suitable amount of black copper,the elimination of the copper contained in the said slag is effected by" acts as a purification agent for the black copper. i i

This actionis due to the fact that the copper contained by the slags obtained inthe of black copper and requires a large -con DE- 'HQBOKEN, or r onoxnmLnz-nnynns,

,"nnninrneior corrnn During'the smeltingoperation the oxidefof copper reacts *with "the; impurities, n ainely 1 with the iron and ferrous metals contained in the black'cop'penan'd prodi ces' the'ir scori fication! I An important advantageof the si Inultaneous smelting o-peratio'n'is that it is exothermalfi It therefore "supplies thefsi nelt-i mg of a mixture of blackcopper andlslag from the refining operation, with i a; portion of the he'at which is necessary for the smelt-1 9". l'n-g, thus saying 7 an "important amount of V p fuel.

The above facts have permitted to bring I into effect a. new process for the refining "of blackcopper, more particularly with a view to-obtaining anodes for the electrolytic re-,

fining.

According'toa characteristic featureof I the present invention, the black copper to be treated is subjected to simultaneous 'smelt= mg with thesl-ag containing copper in oxide form, obtained from the, subsequent refining I operations. The smelting is preferably carfried out in a shaft furnace of the water- 5 jacket type. The copper thus treated is separated and is further treated in anotherfurq" naceuntil obtaininganodecopper.

Bythe said smelting a complete or partial purification of the black copper will be ob- 6 tained' according to therati'o black copperslag which it has been possible to produce.

In the case of a normal black coppen th at containinga high percentage of copper (for instance 98 percent),the copperob- 5 'tained by the. ,snieltin with slag which con- .Jtains oxide of copper, is generally sufliciently purified that itdoes not requireanyother subsequent oxidation thangthat necessary for v the elimination ,of impurities other than go those "formed by metals of the ferrous group. This operation. s then carried out inanjanode furnace.

Whenlrowovfilthe 'black'copper is very impure per cent 'ofcopper), it is possible thatthe (containingfor instance to ,96 i

tinue in another furnace the refining operation which was commenced by the smelting in the water-jacket furnace.

In this case, the purifying operation in the Water-jacket furnace is followed by a blasting ofthe part-iall3 purified copper obv tained in the water-jacket furnace, inside a 1 nace.

mains alloyedwith the copper whilst the tilting cylindrical furnace, or converter, provided with nozzles for the blast and with a device permitting to heat the apparatus. The blasted co'pperis afterwards removed into a revcrberatory furnace where it is subjected to the operation of poling, and is cast in the form of anodes, or the poling may becarried out in the tilting furnace itself andthe copper obtained may be cast direct. The treatment of very impure black copper is thus'eifect-edinvarious apparatus, each adapted to the various treatments to whichthe blackcopperis to be subjected.

In this process the slag obtained in the converter and which contains copper in OX- ide form, is re-treated at the same time as black copper, inside the wateracket fill"- The major part of-the nickel remajor part of the cobalt passes into the slag,

and the latter can be treated direct for obtaining a rich cobalt alloy.

I claim:

1. A process for the preliminary refining of black copper containing a high percentage of impurities of the iron group consisting of iron, nickel and cobalt, comprisingthe smelting of the black copper inside a V shaft furnace together with slag containing copper oxides and without the addition of lime, so as to concentrate on the one side the copper, and on the other side the said 

